Intraossärer

Intraossärer (intraosseous) refers to procedures and techniques that involve delivery into the bone or the bone marrow cavity. In medical use, intraosseous access is the most common form, enabling administration of fluids, medications, or withdrawal of blood through a needle inserted into the cancellous bone.

In emergency medicine, intraosseous access is used when intravenous access is difficult or time-critical. It is especially common in pediatric patients and in adults experiencing shock, severe dehydration, or other conditions that impede venous access. IO administration allows rapid delivery of crystalloids, blood products, and emergency medications.

Anatomy and sites: The needle is placed into the medullary cavity of cancellous bone. Common sites include the proximal tibia on the medial surface, distal tibia, and proximal humerus. Less frequently used sites include the sternum and iliac crest. Placement in the metaphyseal region helps minimize injury to growth plates in children.

Devices and technique: IO devices range from manual needles to powered drill or automatic devices. After placement, the system is flushed with saline to confirm patency and to start infusion. IO access is usually intended as a temporary measure until intravenous or central venous access is established.

Safety, limitations, and complications: Contraindications include localized infection at the insertion site, fracture at the target bone, severe osteoporosis, or known bone abnormalities. Potential complications include infection (osteomyelitis), fat embolism, extravasation with tissue necrosis, pain, and rare damage to growth plates. Proper technique, asepsis, and site rotation minimize risk.

See also: intraosseous infusion, emergency medicine.